The present invention relates to an apparatus for supporting, conveying and steering articles, and more particularly to an apparatus for diverting a continuous succession of articles supplied in a single lane to supply plural lanes.
Apparatus for supporting, conveying and diverting articles are known in the art. The known apparatus typically is between an upstream conveyor and one or more downstream conveyors. The known apparatus is typically supplied by the upstream conveyor with a single column of a continuous succession of articles. The articles are supported, conveyed, and diverted by the known apparatus to supply plural columns of articles, as for supplying plural downstream conveyors and the like. For that purpose, the known apparatus typically comprises a horizontal section of rollers which are positively driven to rotate about horizontal axes and are operably pivotable about vertical axes. The rollers provide upper rolling surfaces upon which the articles can be supported and conveyed. In addition, the rollers are operatively pivotable from a normal position corresponding to conveying articles in a straight path to off-normal positions, corresponding to diverting articles.
The prior art apparatus are deficient at accurately steering the articles without such costly penalties as slowing down the throughput of articles or increasing the size and complexity of the apparatus. Steering accuracy is typically sacrificed when articles traveling at high speed approach rollers at an angle, even if the angle is shallow. Additionally, steering accuracy may be sacrificed when articles traveling at a moderate speed approach rollers at too severe an angle. Either way, the result is that traction is broken between the rollers and the articles. Consequently, the articles change travel directions in curved paths prescribed more by physics and inertia than by machine-selected control. To date, the preferred and conservative way to achieve steering accuracy is to slow down the throughput of articles. However, slowing down the throughput is costly for high-speed conveyor lines.
Further deficiencies in the prior art apparatus concern the longitudinal gaps required between successive articles. Gaps are costly because a high speed line with large gaps between successive articles provides only a low throughput of articles. Part of the need for gaps between successive articles relates to the time needed for repositioning the rollers between the passage of a leading article and the oncoming of a trailing article. Another need for gaps between successive articles relates to the sensitivity of the apparatus to the disordered supply of articles. Some of the prior art apparatus are especially sensitive to disordered supply such as the early arrival of a trailing article, because the apparatus has not had time to make a steering decision and position the rollers accordingly. Such articles then are steered in error. For such disordered supply, the typical solution has been to provide overgenerous gaps, and to suffer losses in throughput as a consequence.
What is needed to solve the deficiencies of the prior art is an apparatus which has a high throughput for articles, and which can steer articles at a sever angle without breaking traction between the rollers and the articles, as well as having the ability to make independent steering decisions on the basis of the arrival of each article, and which is rugged, compact, and long-lasting.